GNSS
- What are the limits of GNSS time accuracy?
The limits are not about radio or geometry. GNSS time is a prediction, so its accuracy is bounded by how good the corrections are — and corrections are forecasts of errors that have not happened yet.
- Which GNSS constellation keeps the best time?
Folklore says Galileo. BIPM measures it daily, per constellation, and publishes the answer — and over fourteen months the folklore does not hold up.
- Choosing a GNSS timescale for syncing datacenter clocks
You are not choosing a receiver so much as choosing whose timescale you end up on. There are three ways to do it, they differ by a factor of a hundred in cost, and most datacenters should take the cheapest.